Project Summary Regularly done physical activity (PA) has been associated with numerous health outcomes, yet the majority of Americans still struggle to meet minimum PA guidelines, making physical inactivity an ongoing, significant health challenge particularly among women and minorities, especially Hispanics. Traditional behavior change programs have had little sustainability, in part attributable to ecologic factors part of the complex system in which individuals exist, grounded in environment, policy, cultural or social origins. The Ecologic Model of Physical Activity (EMPA) identifies micro-, exo-, meso- and macro-environmental influences on PA that rapidly shape behavior back to its origin after individual interventions are completed and posits that both relatively static micro-environmental factors such as the presence or absence of a PA resource, as well as dynamic exo- and meso-environmental factors such as the shared goals, supportive social networks, and frequent prompts, are critical in the adoption and maintenance of PA. Increasing PA is not only a US but also an international health priority, suggesting collaborative, transdisciplinary strategies are needed to address this growing public health problem. This project aims to capitalize on the unique opportunities presented in the City of Houston and an existing collaboration between the University of Houston and University of Guadalajara. We will develop a partnership to refine the EMPA and a collaborative scientific research agenda focusing on PA maintenance across the lifespan with particular attention to Hispanic women and children. The Texas Obesity Research Center (TORC) in the Department of Health and Human Performance at the University of Houston (UH) will serve as a framework organization to support the collaboration and research agenda and will rely on longstanding organizational, scientific and community ties. The partnership will hold monthly teleconference meetings, semi-annual face to face meetings, and a research conference in year 2 to accomplish project objectives. The monthly teleconferences and semiannual meetings will aid the development of shared trust among the scientific partnership and the refining of the model. Partners will share successes of moving the science, both in terms of refining theory but also in terms of reviewing empirical findings to consider best practices and future directions. Project findings will be disseminated via four scientific publications that will (1) review and critically evaluate PA research in Hispanics, (2) develop and/or modify existing theoretical models to propose a more refined model based on available data, (3) develop consensus guidelines and posit recommendations for research, practice and policy derived from empirical data and theory, and (4) document the evaluation process and describe lessons learned. Findings will also be included in grant reports and be presented at scientific meetings. It is expected that this project will provide a forum for the development of a scientific collaborative structure that will support an eventual research project with a focus on addressing and eliminating health disparities and improving PA among Hispanics. PUBLIC HEALTH RELEVANCE: Physical inactivity rates are higher among Hispanics than Whites, despite increased vulnerability to related health compromising conditions. The problem is particularly evident in the United States and Mexico. A collaborative, transdisciplinary approach and model that incorporates individual, social and environmental influences of physical activity behavior and maintenance is needed to address this growing public health problem.